1.绝对定位和固定定位的方法
.div1{ width:100px; height:100px; position:absolute; left:50%; top:50%; margin-left:-50px; margin-top:-50px; background: red;}
2.绝对定位和固定定位加margin:auto实现
.div1{ position:absolute; width:100px; height:100px; margin:auto; left:0; top:0; right:0; bottom:0; background: green;}
3.table-cell实现
.box{ width: 300px; height: 300px; display: table-cell; vertical-align: middle; text-align: center; border:1px solid #000; }.box div{ width:100px; height:100px; margin:0 auto; background-color:red; }
4.针对行内元素
div{ height:100px; text-align:center; line-height:100px; }
5.利用css3的属性flex
.box{
width: 500px; height: 500px; display:flex; justify-content:center; align-items:center; border: 1px solid #666; } .div1{ width:100px; height:100px; background-color:red; }<div class="box">
<div class="div1"></div> </div>